Experiment Investigation and Optimization for Slider Bonding Process to Enhance the Shear Strength of Epoxy Adhesive Joint

The shear strength of adhesive bonding between the slider and suspension greatly affects the quality of the hard disk drive. Therefore, this paper intends to determine the optimal slider bonding parameters which can maximize the shear strength of the adhesive joint. The response surface methodology (RSM) and optimization are employed to investigate the effects of five process parameters to the shear strength of the adhesive joint. Next, the central composite design which is a RSM is conducted. The analysis of variance is used to identify the significant terms of the quadratic regression model. Then, the optimization approach is utilized to determine the optimal process parameters with the mean shear strength of 257.62 gf. The confirmation experiment to validate the quadratic model reveals that the prediction error is only 1.6% which is acceptable. Next, the regression model is also used to define the optimal process conditions under the capacity constraint. In this case, the regression model can provide the accurate prediction of the shear strength with 1.14% error. In conclusion, the RSM and optimization approach can effectively yield the optimal process parameters that can enhance the shear strength of the adhesive joint to achieve the appropriate quality level

Design and Analysis of the Slider Shear Test System Using Nested GR&R Measurement System

The shear strength of the adhesive bonding between slider and suspension is a vital characteristic for head gimbal assembly. The current shear test method has shown improper failure modes; therefore, a new system has been designed to improve the slider shear test. Six sigma framework was applied to redesign the slider shear test system. The finite element method confirms that new design concept is acceptable because it can yield the correct failure mode of shear test. Next, the measurement errors of the new shear test system are assessed using nested gage repeatability and reproducibility (NGR&R). NGR&R of new shear test system is less than 10% which is an adequate gage. Then, the results of simulation also confirm that decreasing of measurement error can significantly reduce the over reject rate. In conclusion, new shear test system can be effectively used to reflect the real product quality and to obtain more accurate process capability resulting from the correct failure mode of testing